Achievable MCS rates for various SNR

If you ever had the doubt, why my WiFi speed is slow even while i stand next to the Access point or with having good coverage. Just having a strong wireless coverage/ signal  alone will not help you to achieve the highest possible  speed on wireless. We need to consider the floor noise too. The following chart has MCS values for  SNR(signal to noise ratio)

This can come handy when calculating the throughput on wireless Networks:






802.11 Statistic value for reference:

I was always wondering, if there is some reference value i could use when i troubleshoot a  wireless and RF issues. Particularly  when it comes to  duty cycle /channel utilization, time delay and retries. Here are some values and you can keep this as reference for your Wlan troubleshooting:

#802.11 statistics values for reference:
Retries: less than 20%
Loss: not exceed 1% packet loss
Channel utilization: keep it under 50-40% and possible 30%
Noise: should not exceed -92dBm, Where -80dBm is bad.
SNR:should be greater than 25dB
Signal strength : should be around -67 or -65 even in the edge of the cell.
Time or delay: Keep it below 100 and possible <300 ms



Infrastructure Wireless with Fortinet | August 2016 update

Since this is already back to school time, the WiFi network Engineers would already see lot new devices in the school WiFi network and also students might have got some more devices added to  already high density environment.

Forinet has some recommendations to help you with some stable Wifi network.





RF signal Attenuation Values in common office constructions

–WiFi signal gets attenuated during the signal propagation depending upon the object or construction material

–Here are some object you could find in common office space and its attenuation values.

Examples of the attenuation values of common office construction:
Plasterboard wall 3dB
Glass wall with metal frame 6dB
Cinder block wall


Office window 3dB
Metal door 6dB
Metal door in brick wall 12.4dB
As a result, a typical small office could have several plasterboard walls equating to an additional 9 to 12dB of attenuation. Metal doors and glass walls could sometimes be in the way of the propagation of the signal, causing even larger amounts of attenuation. Of course this decreases the operating range of the access points

Aruba WLAN Deployment Recommendation

–Aruba has the following recommendation during the 2015 Atmosphere

–The Following values with a smart WiFi design is Essential in a high density deployment.